Crystalline transition metal dichalcogenide films and methods of making same

Abstract

Methods of making molybdenum sulfide (MoS2) on a stretchable substrate are disclosed. The method includes magnetron sputtering MoS2 onto a stretchable substrate, such as a stretchable polymeric material, at low temperatures to form a film precursor, and illumination annealing the film precursor to form high quality MoS2. The illumination source may be a laser or other source of radiation. Also, two-dimensional nanoelectronic devices made by the methods and/or from the high quality MoS2 are disclosed.

What is claimed is: 
     
         1 . A method for making a transition metal dichalcogenide film, the method comprising:
 providing a precursor film comprising an amorphous transition metal dichalcogenide film deposited on a substrate by a physical vapor deposition process at a temperature in a range from about 20° C. to about 250° C.;   illumination-based annealing the precursor film, thereby changing the amorphous transition metal dichalcogenide film to a crystalline transition metal dichalcogenide film.   
     
     
         2 . The method of  claim 1 , wherein the substrate is a flexible substrate material. 
     
     
         3 . The method of  claim 2 , wherein the flexible substrate material comprises polydimethyl siloxane (PDMS), 2-methacryloyloxyethyl phosphorylcholine (MPC), or one or both copolymerized with dodecyl methacrylate (DMA). 
     
     
         4 . The method of  claim 1 , wherein the physical vapor deposition is magnetron sputtering, pulsed laser deposition, thermal evaporation, or electron beam evaporation. 
     
     
         5 . The method of  claim 1 , wherein the amorphous transition metal dichalcogenide film has a thickness less than 10 nm. 
     
     
         6 . The method of  claim 1 , wherein the transition metal dichalcogenide film comprises one or more of molybdenum sulfide and tungsten sulfide. 
     
     
         7 . The method of  claim 1 , wherein the laser annealing comprises exposing the amorphous transition metal dichalcogenide film to laser radiation having an intensity of about 0.5 mW/μm 2  to about 20 mW/μm 2  for about 0.1 to about 100 seconds. 
     
     
         8 . The method of  claim 7 , wherein the intensity is in a range of about 2 mW/μm 2  to about 20 mW/μm 2 . 
     
     
         9 . The method of  claim 1 , wherein the intensity is in a range of about 10 mW/μm 2  to about 20 mW/μm 2 . 
     
     
         10 . The method of  claim 1 , wherein laser annealing comprises selectively turning an illumination source on and off repeatedly to form a pattern of crystalline transition metal dichalcogenide film in the precursor film. 
     
     
         11 . The method of  claim 10 , wherein the illumination source is a laser. 
     
     
         12 . An electronic device comprising a patterned crystalline transition metal dichalcogenide film made according to the method of  claim 10 . 
     
     
         13 . An electronic device comprising a crystalline transition metal dichalcogenide film made according to the method of  claim 1 . 
     
     
         14 . A sensor comprising a crystalline transition metal dichalcogenide film made according to the method of  claim 1 . 
     
     
         15 . A sensor comprising a crystalline transition metal dichalcogenide film made according to the method of  claim 2 .